Tropical habitats may contain more than a third of the world's plant and animal species; Costa Rica alone is home to one of the highest levels of biodiversity per unit area in the world, and stands at center stage in worldwide conservation efforts. Within such regions, the use of state-of-the-art digital mapping technologies--sophisticated techniques that are relatively inexpensive and accessible--represents the future of conservation planning and policy. These methods, which employ satellites to obtain visual data on landscapes, allow environmental scientists to monitor encroachment on...